Abstract

A new Proton Induced X-Ray Emission (PIXE) set-up has been designed and built at the Tandem Accelerator of the University of Cologne. The PIXE installation is used for the determination of elemental composition of thin samples or sample surfaces. The set-up was calibrated and tested with various types of samples. The experiments have been automated and the standard analogue based acquisition system has been replaced by a digital one based on the XIA DGF-4C modules. A small Peltier-cooled XFlash detector has been generally in use and brings many advantages when compared with common Si(Li) detectors. A scanning device can be used for macro-scanning of the surface of PIXE samples and the 2D elemental distribution can be determined. The absolute analysis of the sample composition with a commercial program GUPIX is described. Representative analysis of various samples is presented and compared to literature values or to the results of the PGAA method. The PIXE installation is now ready for routine use. A new Prompt Gamma-Ray Activation Analysis (PGAA) facility is now being designed for the research reactor FRM-II in Garching by Munich. The PGAA instrument at FRM-II will use a beam of cold neutrons for the determination of the elemental and isotopic composition of a sample bulk. A number of Monte Carlo simulations were performed to obtain the most convenient beam guide geometry for the cold neutrons; first to keep the neutron flux as high as possible and also to find out, how to focus the neutrons to a small spot of 1x1 mm^2. The divergence of the neutron beam was also part of the study. The challenging task is to make the PGAA facility flexible for four different instrumental set-ups: standard PGAA, Position-Sensitive PGAA, Cold Neutron Tomography and an Ge Array for nuclear structure experiments. The expected parameters of the PGAA facility at FRM-II are then compared to the former one at Paul Scherrer Institute (PSI) in Switzerland. In close cooperation with the PGAA group at the Budapest Neutron Centre (BNC) in Budapest, interesting geological samples were measured and analyzed. Small amounts of samples (100 - 300 mg) were analyzed to demonstrate the reliability of the PGAA analysis even for such cases. The results of the analysis for geological standards and meteorites, both either as stones or as homogeneous powders are presented and discussed. PIXE and PGAA analysis for the same samples were performed, the results were compared and conclusions about when PIXE and PGAA are competitive and when complementary are given. In case of PGAA, comparison with Instrumental Neutron Activation Analysis (INAA) is also discussed.